From b8f8534b10b6ee3cec5e49682d7e0c4796cdccea Mon Sep 17 00:00:00 2001 From: Tingwei Zhang Date: Mon, 5 Oct 2020 10:13:17 +0300 Subject: stm class: ftrace: Use different channel accroding to CPU To avoid mixup of packets from differnt ftrace packets simultaneously, use different channel for packets from different CPU. Reviewed-by: Steven Rostedt (VMware) Signed-off-by: Tingwei Zhang Signed-off-by: Alexander Shishkin Link: https://lore.kernel.org/r/20201005071319.78508-7-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/stm/ftrace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/hwtracing') diff --git a/drivers/hwtracing/stm/ftrace.c b/drivers/hwtracing/stm/ftrace.c index c694a6e692d1..3bb606dfa634 100644 --- a/drivers/hwtracing/stm/ftrace.c +++ b/drivers/hwtracing/stm/ftrace.c @@ -37,8 +37,10 @@ static void notrace stm_ftrace_write(struct trace_export *export, const void *buf, unsigned int len) { struct stm_ftrace *stm = container_of(export, struct stm_ftrace, ftrace); + /* This is called from trace system with preemption disabled */ + unsigned int cpu = smp_processor_id(); - stm_source_write(&stm->data, STM_FTRACE_CHAN, buf, len); + stm_source_write(&stm->data, STM_FTRACE_CHAN + cpu, buf, len); } static int stm_ftrace_link(struct stm_source_data *data) @@ -63,6 +65,7 @@ static int __init stm_ftrace_init(void) { int ret; + stm_ftrace.data.nr_chans = roundup_pow_of_two(num_possible_cpus()); ret = stm_source_register_device(NULL, &stm_ftrace.data); if (ret) pr_err("Failed to register stm_source - ftrace.\n"); -- cgit v1.2.3